Final answer:
A latent function of September 11, 2001, is an outcome that is hidden or unintended but still impactful, such as changes in security measures and increased patriotism.
Step-by-step explanation:
The best description of a latent function of September 11, 2001, is 1) A function that is hidden or unintended but still has an impact. Latent functions are outcomes that are not the primary objective of a social process but occur as a secondary effect. For instance, while the manifest function of the September 11 attacks was to cause terror and destruction, latent functions included the unintended but impactful outcomes such as increased patriotism, changes in airport security protocols, and fostering a sense of global unity against terrorism. In the context of September 11, 2011, a latent function could be the increase in security measures and surveillance that were put in place after the terrorist attacks. This was not the intended purpose of the attacks, but it had a significant impact on society.